Earthmoving machines such as track type tractors, motor graders, scrapers, and/or backhoe loaders, have an implement such as a dozer blade or bucket, which is used on a worksite in order to alter a geography or terrain of a section of earth. The machine and/or the implement may be controlled by an operator or by a control system to perform work on the worksite such as achieving a final surface contour or a final grade on the worksite. Positioning the implement, however, is a complex and time-consuming task that requires expert skill and diligence if the operator is controlling the movement. Thus, it is often desirable to provide autonomous control of the machine and/or the implement to simplify operator control.
For autonomous control, it is sometimes necessary to determine the accurate ground speed of the machine to compare against a desired ground speed value for the control systems. Some machines use ground penetrating radar (GPR) and other ground based position systems to determine the ground speed. GPR components, however, are prone to failure, which may introduce errors in the ground speed determination and are often easily covered with dirt, which an operator must get out of machine, crawl under it, and remove the debris from the mounted radar. Further, radar components due to location can be damaged by rocks.
For example, U.S. Pat. No. 5,8640,480 to Jayaraman et al. (“Jayaraman”) disclose a method for determining pitch and ground speed of an earth moving machine. Jayaraman discloses an automatic control system that includes a ground speed sensor that senses the ground speed of the earth moving machine and responsively produces a ground speed signal. Jayaraman teaches that the ground speed sensor is suitably positioned on the bulldozer and includes for example, a non-contacting ultrasonic or Doppler radar type sensor.
The disclosed systems and methods are directed to overcoming one or more of the problems set forth above.